The quick connect coupler of my U.S. Pat. No. 3,695,139 was developed for connecting threaded bolts to various types of devices, as in attaching plates, forms, rails or the like to concrete or other types of walls. These quick connect couplers included a plurality of segments threaded on the inside, for engagement with bolt threads and forming essentially a circle around the bolt, with resilient rings for holding the segments together in annular relationship. The segments, when so assembled, provided a convex frusto-conical surface or cone at one end and a concave frusto-conical surface or bevel at the opposite end. A conical bevel seat, in position to engage the cone end of the segment assembly, moved the segments into closer engagement with the bolts until the inside threads of the segments became tight on the bolt threads. For quick connection, a nut assembly, which included the segments, was provided with a conical spreading surface in juxtaposition to the concave surfaces of the segments, so that when the nut was pressed onto the bolt, the segments could be pushed against the cone and spread apart against the force of the resilient rings, until the end of the nut bearing the concave seat abutted against the article from or through which the bolt extended. Then, the segments would move inwardly for engagement of the inside threads of the segments with the bolt threads. Then, a few turns of the nut would tighten the threads together.
The present invention utilizes certain principles of my prior patent. However, when the precise constructions disclosed therein were attempted to be applied to a quick or rapid connector for fluid conduits, a number of problems were encountered. One problem was caused by the limitations on the total diameter of the connector and also the number of threads which could be provided on the connector. As the diameter of a conduit increases, the tendency for cross threading of the segment threads with the conduit threads increases, since a slight angular tipping of a segment, unobjectionable with a small bolt, magnifies the difficulty many times, when the segments are considerably larger in diameter and extend around a larger diameter conduit. Similarly, the use of more than two segments increased the problems of cross threading, although my additional prior U.S. Pat. No. 3,797,336 for "Quick Connector Nut" does disclose a pair of essentially semicircular segments in a nut adapted to be pushed onto a bolt and then tightened by turning a few turns. Also, the larger diameter and the necessity for limiting the amount of travel prior to tightening required a limited number of threads which again increased the possibility of cross threading. In addition, it was found that the segments of larger diameter tended to hang up, as it were, on a threaded conduit to which it was being connected and thus failed to rotate with the housing or the like in which mounted. The problems in thread alignment and quick snapping of the segment threads onto the threads of a conduit were increased by the relatively lesser force exerted by the normal size of wire used in forming the spring rings for holding the segments together. In addition, axial misalignment of the segments proved to be a problem, again contributing to cross threading, in addition to tipping of the segments. Another problem produced by fluid conduits, not present in ordinary bolt connections, is that of sealing the conduit against leakage. This is ordinarily produced by providing a seal ring, preferably on the connector, and against which is abutted a pipe or the like on which the connector is to be installed. The presence of the seal ring means that the relative movement between the pipe or the like and the connector is limited, since for conservation of space, internally threaded segments must be disposed as closely as possible to the seal ring.
The principal prior type of quick connectors for fluid conduits comprised toggle clamps for holding a conduit against a pipe, but unless the toggles are completely seated, the entire connector may pop off the pipe. Also, in the case of fire plugs, vandals may batter the pipe threads, making it difficult to screw a fire hose coupling onto the threads.
Among the objects of this invention are to provide a connector for fluid conduits having threaded segments, which will readily and quickly engage the threads of conduit; to provide such a connector in which tipping or axial misalignment of the segments is substantially avoided, thereby reducing to a minimum the possibility of cross threading; to provide such a connector in which the force produced by resilient means for holding the segments together does not require an increase in proportion to the diameter of the conduit; to provide such a connector in which the segments are positively connected when relative rotation of an enclosure for the segments is produced to cause the threads to tighten; to provide such a connector which is particularly useful with a conduit in which a seal ring is abutted by a pipe or the like to which the connector is being attached and the problems resulting from limitation on relative movement of the pipe or the like into engagement with the seal ring are overcome; to provide such a connector which reduces lateral play of the edges of the segments; to provide such a connector which may be readily installed on a pipe or the like with damaged threads; to provide such a connector which will not pop off, even though not completely tightened; and to provide such a connector which is efficient, effective and reliable in use, as well as relatively long wearing.